Add assets for Cisco SD-WAN integration (#17502)

* Add assets for Cisco SD-WAN integration

* Sync labeler conf

* Fix manifest

* Fix manifest (again)

* Fix assets (again)

* Add NDM as codeowners for Cisco SDWAN

* Fix link

* Improve monitor description

* Network jitter is measured in ms

* Shorter monitor descr

* Caps

* Add beta notice

* Add beta notice

* Fix typo

* Update beta warning

* Fix source name

* Update monitors

* Change reboot monitor threshold

* Update dashboard

* Update cisco_sdwan/assets/monitors/device_reboot.json

Co-authored-by: Esther Kim <esther.kim@datadoghq.com>

* Update status metrics description

* Fix bps description

* quotes

* typo

* typo

* Group by device namespace in query value widgets

* fix unreachable widget color

* Remove oauth field from manifest

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Co-authored-by: Esther Kim <esther.kim@datadoghq.com> 9aafcf2